1. Field of the Invention
The present invention relates to a vacuum processing system for processing a target object within a vacuum atmosphere, and particularly to an improvement of a semiconductor processing technique. The term “semiconductor process” used herein includes various kinds of processes which are performed to manufacture a semiconductor device or a structure having wiring layers, electrodes, and the like to be connected to a semiconductor device, on a target object, such as a semiconductor wafer or a glass substrate used for an FPD (Flat Panel Display), e.g., an LCD (Liquid Crystal Display), by forming semiconductor layers, insulating layers, and conductive layers in predetermined patterns on the target object.
2. Description of the Related Art
In manufacturing semiconductor devices and FPDs, various processes, such as film formation processes, thermal processes, dry etching processes, cleaning processes, are performed using process gases within vacuum process chambers. A process chamber for performing a vacuum process of this type is connected through a gate valve to a transfer chamber provided with a transfer robot disposed therein (for example, Jpn. Pat. Appln. KOKAI Publication No. 3-87386). The transfer robot is used for transferring a target object (such as a semiconductor wafer or glass substrate) between the transfer chamber and process chamber. At this time, this transfer is performed without setting the process chamber opened to the atmosphere. According to a transfer chamber of a first type, the interior of the chamber is always maintained in a vacuum state. According to a transfer chamber of a second type, the chamber is configured to adjust the inner pressure between atmospheric pressure and a vacuum.
Where a transfer chamber of the first type is used, the transfer chamber is connected through a gate valve to a load-lock chamber capable of adjusting the inner pressure between atmospheric pressure and a vacuum. The load-lock chamber is connected to an atmospheric pressure space through a door valve disposed on a side opposite to the gate valve. The load-lock chamber is used for temporarily placing a target object transferred between the atmospheric pressure space and vacuum space. Where a transfer chamber of the second type is used, the transfer chamber itself is structured as a load-lock chamber capable of adjusting the inner pressure between atmospheric pressure and a vacuum. The transfer chamber of the second type is connected to an atmospheric pressure space through a door valve disposed on a side opposite to the gate valve.
The gate valve is a switching valve vertically partitioning a passage for a target object. The gate valve is normally set in the closed state, and is temporarily set in an opened state to allow a target object or an arm of a transfer robot to pass therethrough. When the gate valve disposed between a vacuum process chamber and a transfer chamber is opened, a target object can be transferred between the process chamber and transfer chamber.